Annealing glass sheets or plates.



No. 741,494. PATENTED 00T. 13, 1903.

` H. K. HITCHCOCK. l ANNEALING GLASS SHEETS 0R PLATES.`

APPLICATION 'FILED JULY 30. 1.902. y im MbDEL. z SHEETS-SHEET l1.

INVENTOR v mL/KJ WITNESSES.: 56M @au No. 741,494.- PATBNTED UGT. 13,190s.

H.K.H1TGHG00K,

ANNEALING .GLASS SHEETS 0R PLATES. APPLICATION FILED JULY so. 1902.

UNITED STATES Patented October 13, 1903.

PATENT OFFICE.

AANNEALING GLASSSHEETS OR PLATES.

SPECIFIGATION forming part of Letters Patent N o. 741,494, dated October13, 1903.

' Application filed .Tuly 30, 1902. Serial No. 117,639. (No specimens.)Y

{Il} all whom t may concern: i

Be it known that I, HA'LBERT K. HITGH-, COOK, a citizen of the UnitedStates, residingf at Walton, in the county of Allegheny and? State ofPennsylvania, have invented or discovered certain new and useful Improvements l in Annealing Glass Sheets or Plates, of which improvementsthe following is a specitication.

It has been found in annealing sheets or plates of glass that the edgescool more rapidly than other parts and that the contraction of the edgeswill-produce wave-like surfaces, thereby necessitating long-continuedgrinding to produce even plane surfaces.

The object of the invention described herein is to provide for asubstantially uniformv cooling and contraction.

` erators.

The invention is hereinafter more fully described and claimed.

In the accompanyingdrawings, forming a part of this specification,Figure 1 is a plan View of affurnace adapted to the practice of myinvention. Figs. 2 and 3 are sectional elevations on planes indicated bythe lines II II and III III, Fig. 1; and Fig. 4 is a View in the natureof a diagram illustrative of my invention.

In the practice of my invention the-annealing lear or kiln is providedwith suitable means whereby the loss of heat byradiation from dierentportions of the sheet or plate in the kiln can be controlled. Aconvenient manner for effecting such controlV is shown in the drawingsand consists in providing suitablemeans for applying a regulated heat todierent portions of the compartments 1 of the leer or kiln. Thisapplication of heat can be effected by providing heating-chambers 2, 3,and 4. outside of the walls proper of the compartments. The chambers areprovided with suitable outlets, so thatthere may be a 'circulation ofthe heat through such chambers, and it is preferred that eachheatingchamber should have independent heat-genehambers 2 under thefloors of the annealing-compartments are connected by lfines 5 5o with astack 6, and burners 7 from the supplypipes 8 extend up into saidchambers. These burners are preferably arranged in or approxi- As shownin the drawings, the.

with the top chambers-4, which are provided with outlet-dues 9. Burners10 extend fromthe supply-pipes 8 into the side chambers 3- near theirlower portions,and the heat therefrom flows up into the top chambers. Asthe initial or charging compartment has heatingchambers on three sidesonly and the other compartments on only two sides, (saidheating-chambers being arranged in the outer walls of saidcompartments,) portions of the upper chambers might not be sufficientlyheated from ythe side chambers. Uniform heating of the top chambers isattained by means of burners 11, extending into the portions of .the topchambers not in the line of flow of heat from the side chambers.

The curtain-walls 13, separating the compartments, are made hollow, asshown, and connect at thev ends with the side chambers 3, so that saidwalls will receive some heat from the side chambers.

It will be readily understood by those skilled in the art that othermeans ymay b e employed for maintaining any desired heat in any portionof each compartment, and hence the broader claims are not limited to anyspecific means for applying heat to the sheetsor plates in the leer orkiln.

It is characteristic of my improvement that by the proper regulation ofthe heating devices the cooling down, and consequent con-v traction, ofthe sheets or plates can be made uniform throughout, thus avoiding anydistortion' of parts by the prior cooling and contraction of otherparts. It will be understood that each compartment is maintained at alower temperature than the preceding compartment. If the edges of thesheet or plate are too cool when charged into the leer, such edges maybe heated up by increasing the heat in the bottom and side chambers.

In Fig. 4 is shown a portion of a plate of glass. As the portion of theplate outside of the line a c, having a radiating-surface represented bythe line a b c, will contain less heat units than the portion betweenthe lines a c and d c, the radiating-surface of such por- IOO tion beingrepresented by the line a d and equal to the surface ct b c, it followsthat the latter portion Will cool more slowly than the edge portion ctI) c. Hence to prevent the more rapid cooling of the edge portion theradiation therefrom is reduced or checked by the propel' regulation ofthe heat-generators, as described. In case the edges have becomecomparatively cool before the sheet or plate is stowed in the kiln orleer, by increasing the heat at the edges of the sheet or plate they maybe rendered sufiiciently plastic to allow the Wrinkles or Waves in thebody portion to fiatten out.

While I have shown and described with some particularity an apparatusadapted to the practice of my invention, the claims herein are notlimited to the employment of suc-h specific forni of apparatus, whichforms no part of the subject-matter of this application.

I claim herein as my invention- I. An improvement in the art ofannealing sheets or plates of glass, which consists in bringing allportions of the sheet or plate to a uniform or approximately uniformtemperature and then so regulating the radiation of heat units that thecooling of the sheet or plate shall be equal in all parts, substantiallyas set forth.

2. As an improvement in the art of annealing sheets or plates of glass,the method herein described which consists in so regulating theradiation and consequent cooling of the edges of the sheets of glassthat the contraction along such edges will be approximately simultaneousand uniform with the con traction of other portions, substantially asset forth.

In testimony whereof I have hereunto set my hand.

HALBERF K. HITCHCOCK.

Witnesses:

.DARWIN S. WoLooT'r, F. E. GAITHER.

